Spine fusion is the current gold standard of care for low back pain today. Spinal devices and procedures currently available do not always completely eliminate the source of a patient's pain or restore the patient's natural disc function or range of motion. There is also some evidence that shows that fusion at a particular level may cause further degeneration to the discs at adjacent levels. Spinal Arthroplasty nowadays is becoming coming more popular as it potentially can significantly reduce pain, restore nearly full range-of-motion, and reestablish natural disc height thereby keeping the facet joints and surrounding ligament structure and tissue intact. Artificial disc prostheses and disc augmentation techniques have been under development for over 35 years. The evolutionary course of artificial disc product development has included an array of product designs, materials and instruments. Mechanical, elastometric and physiological solutions have been devices designed to replace the nucleus or a portion of the disc annulus.
Despite all the R&D, animal testing and human clinical trials so far spent on the problem, the preparation of the disc to accommodate the device is not well established. There is a need of a means to produce a precise void or cavity within the disc in a time-efficient manner while maintaining the viability of the vertebral endplates and integrity of the annulus fibrosis. If a procedure cannot properly manage anatomy preservation, it may not fully succeed.
Currently, mechanical devices such as rongures are being used without the ability to completely remove the nucleus material and the attempt often is time consuming. Many practitioners have dismissed lasers and electrosurgical devices on the ground that they produce excessive heat that can compromise the integrity of the endplates and annulus.
Various mechanical devices are described in the following patent publications: Nos. US2003/0040800A1 and US2004/0092943A1. These patents, the contents of which are herein incorporated by reference, also give details of the anatomy of the spine, nomenclature, and prosthetics.